Electric circuit breaker



l A 1,626,528 Aplll 9 R. W' GREGORY ELECTRIC CIRCUIT BREAKER Filed July 22, 1925 sheets-sheet 1 April 26 1927. 1,626,528

R. W. GREGORY ELECTRLC CIRCUIT BREAKER Filed July 22, 1925 2 sheets-Sheet 2 Patented Apr. 26, 1927.

UNITED STATES PATENT oFFicE.

:RICHARD WALTER GREGORY, 0F HEXHAM-ON-TYNE, ENGLAND, ASSIGNOR TO ELEC- TBICALIMPROVEMENTS LIMITED, OF NEWCASTLE-UPON-TYNE, ENGLAND.

ELECTRIC CIRCUIT BREAKER.2

Application led July 22, 1925, Serial No.i45,373, and in Great Britain September 24, 1924.

This invention relates to electric circuitbreakers and has articular reference to oilimmersed circuitreakers suitable for use on high voltage systems where a quick break with a long ap is desirable.

A circuit-breaker according to this invention has a spring or gravity-controlled spindle carrying what may be termed retaining contacts cooperating, when the breaker is closed, with. one or more spring-operated contacts which are released by the retaining contacts when the spindle is tripped by tri ger'or like mechanism to effect a sudden an long break in the circuit.

The circuit-breaker is intended to be immersed in oil and the contact making and breaking parts thereof are conveniently mounted on the under side of the lid of a box or tank whilst the tripping mechanism may be placed on top of the lid.

In one convenient construction the spindle is housed in a hollow or tubular support screwed into a threaded boss in the inside of the lid, the top of the spindle passing through an opening in the lid. To the lower end of the support is detachably fixed a contact having two surfaces, which are adliacent to the spindle, inclined or sloped. Near the lower end of the spindle is' mounted a contact block also formed with. inclined surfaces.

On each side of the spindle and its support is an insulator fixed beneath the lid and terminating at its lower end in a hollow membenor housing for a more or less horizontal coiled spring. Electrical ,connections are made in any convenient way to these hollow members or housings. The free end of each of the springs bears a contact block preferably wedge-shaped or having inclined surfaces corresponding to the surfaces on the lixed and spindle-carried contacts previously mentioned. The springs are so mounted and arranged as to be capable of r being extended andV moved sideways sufficiently to allow the wedge-shaped blocks to be slid into the space between the adjacent fixed contact and the spindle-carried contact and when the wedge-Shaped block is in this position the spring is in fairly strong tension. A flexible connection is preferably provided between the conductor and the wedge-shaped block at the end of the spring.

The upper end of the spindle is operativetacts are retained and the circuit remains closed.

When the trigger or other trip mechanism is operated the lever is released, the spindle moves downwards Kunder the action of gravity or a spring and carries with it the contacts fixed to its lower end. This action is assisted by the pull of the springs on the wedge-shaped contact blocks which are pulled quickly through the spaces between the fixed and spindle-carried blocks and a quick long distance break is obtained.

To reset the circuit-breaker the spindle is raised and the trip mechanism latched or engaged so as to hold it, the springs operating the wedge-shaped blocks are exitended and the blocks slid into position.

The trip mechanism may be such that the act of raising the spindle automatically latches .or sets the breakers I/Vhen., as is preferred, the parts are mounted as described on the lid of an oil tank it is necessary to swing the lid back on its hinges for the resetting operation. c

All the contacts are preferably made so that they may be readily detached and fresh contacts substituted vif that is necessary.

The trip mechanism may be hand-operated or operated electromagnetically for instance, through a relay actuated by some known balanced or other protective system.

In the accompanying drawings which illustrate by way ofexample one construction of oil-immersed circuit-breaker according to this invention:

Figure l is a section Figure 2. i Figure 2 is a plan.

Figure 3 is a section mainly on the line 3-3 of Figure 2, and

Figure 4 is a section on `the* line 4 4 of Figure 3 showing the movable contacts released and in their separated positions.

In these figures A is a box or tank adapted to contain oil and having a lid A1 which may be attached to the box and secured in any desired way. The particular example illustrated is a three phase circuit-breaker and is described as such but it is to be understood that the main features of the invenon the line lof through the springs.

tion are applicable to single phase circuitbreakers and Figure 1 shows the principal cooperating parts for one phase. These parts comprise a spindle formed of two rods B B1 joined by insulating material B2 and housed within a tubular member C screwed into a hollow boss D on the inside of the lid A1. The lower rod B1 of the spindle passes through a gland in the end of the tubular' member C which is provided with a contact E having inclined surfaces E1. At the end of the rod B1 is mounted a similar contact F with inclined surfaces F1.

On each side of the tank are conductors G supported in insulators H and connected respectively to wedge-shaped contacts J mounted on the ends of springs K in boxes or housings K1. Electrical connection is made from each boxor housing K1 to its contact J through flexible conductors L so that the current does not necessarily pass Electrical connections from outside are made to the housings K1 through clips K2 supported on insulators K3 fixed on the bottom of the tank, the housings K1 being withdrawn :from the clips K2 when the lid A1 is opened.

When the circuit-breaker is set the spindle in its raised position retains the contacts J as shown in Figure l and electrical connection is established between the two conductors G. The downward movement ot' the spindle and contact F F1 allows the mov able contacts J to fly apart under the action of their springs K and assume the positions shown in Figure 4.

In the construction illustrated there are three sets of parts such as have been described one set tor each'phase and the rods B of each spindle pass through a bar M.

mounted on brackets M1 on the lid A1. The rods B are attached to a cross bar N and springs O tend to force the cross bar N and the spindles downwards to open simultaneously the contacts in all three phases.

Engaging with the cross bar N are pivoted levers P notched at their ends to engage with a rod R mounted in pivoted arms R1. A link S operatively engages this rod R with a tripping electromagnet T which when energized pulls the rod and arms into suoli a position (Figure 4:) as to release the levers l and allow the cross bar N and the spindles to fall under the action of the springs t). Springs R2 are provided to return the arms R1 and rod R- when the magnet 'l is decnergized and the spindle can be raised again b y depressing the free ends of the levers l which are rounded at their lower edges so that they ma press the rod R outwards until it can slip into the notches in the levers P and hold the spindles in their raised positions.

When tluis reset and after opening the lid, the movable contacts J may be replaced by extending their springs K and slipping the contacts sideways into the spaces bctween the contacts E E1 and F F1.

Barriers U of insulating material are preferably provided between the three phases when the invention takes the forni of a three-phase circuit-breaker as illustrated. These barriers are shown as extending across the tank A.

,It is to be understood that the details of construction may be varied without departing from the scope of the invention as claimed. ,For instance in a three-phase circuit-breaker it is obviously not essential that all three spindles should pass through the lid of the boX or tank and be connected and operated in the wav that is illustrated in the drawings. The spindle of the centre phase might pass through the lid and be operated and controlled in any convenient way and the llower part of that spindle might be mechanically connected to the other spindles so that the contacts carried at their lower ends move simultaneously with the contacts F F1 of the centre spindle.

What I claim as my invention and desire to secure by Letters Patent is 1. In an electric circuit-breaker adapted i to give a quick break and a long gap the combination of a movable spindle, a retaining contact mounted on said spindle, a springoperated contact normally held against the action of itsspring by said retaining contact, and means for moving the spindle to release said spring-operated contact.

2. In an electric circuit-breaker adapted to give a quick break and a long gap the combination of a movable spindle. a retaining contact mounted on said spindle, springoperated contacts normally held against the action of their springs by said retaining contact, and means for moving the spindle to release said spring-operated contacts and trigger mechanism for holding the spindle in the closed contact position and for releasing it.

3. In an electric circuit-breaker the combination of a box adapted to contain oil. a lid for said box. a hollow support dependent from said lid, a spindle slidably mounted in said support. a retaining contact mounted on saidl spindle, spring-operated contacts normally held against the action of their springs hy said retaining contact. a spring tending to move the spindle and the retaining contact to releasey the spring-operated contacts. pivoted means for preventing thc action of said spring, vand electromagnetic means for releasing said pivoted means and allowing said spring. to act.

4. In an electric circuit-breaker. the combination of a box adapted to contain oil. a lid for said hex. a hollow support. dependent from said lid, a contact with inclined faces attached to the bottoni of said support, a spindle slidably mounted in said support, al retaining contact mounted on the lower end of said spindle and having faces oppositely inclined'to those on the contact attached to the support, insulators dependent from the lid one on each side of the hollow support, housings carried by said insulators, an extensible spring in each of said housings, a wedge-shaped contact on the free en`d of each of said springs, a spring around the spindle tending to move the spindle and release the wedge-shaped contacts from engagement between the contacts on "the support and the spindle. a pivoted lever acting to prevent the spring around the spindle from acting, a catch on said lever and electromagnetic means for engaging said catch and holding the lever and for releasing or tripping said 20 lever,

5. In an electric circuit-breaker the combination of a box adapted to contain oil, a lid -For said box, a hollow support dependent from said lid, a Contact with inclined faces attached to the bottom of said support, a spindle slidably mounted in said support, a `retaining contact mounted on the lower end ot' said spindle and having faces oppositely inclined to those onthe contact attached to the support, insulators dependent from the lid one on each side of the hollowsupport. housings carried by said insulators, an extensible spring in each of said housings, a wedge-shaped contact on the free end of each of said springs, insulators mounted on the bottom of the box, and elips'supported by said insulators and adapted to receive the housings when the lid is closed.

In testimony whereof I have signed my name to this specification.

RICHARD WALTER GREGORY. 

